Matrix control circuitry using gate controlled unidirectional signalling devices



March 26, 1968 Filed April 27, 1964 .K. JONES, JR.. ET AL 3,375,497MATRIX CONTROL CIRCUITRY USING GATE CONTROLLED UNIDIRECTIONAL SIGNALLINGDEVICES I 5 Sheets-Sheet l RANK F! RESET f MEANS ROW SELECT MEANS ol l EMEANS 2 ROW LDRNEFI omvsfl DRIVE?! omvafl RESET +75V. MEANS v 1? 0% 0%*5 DRIVER RANK g 5* SELECT MEANS DRIVER I I 18" T fix J 5 J6 DRIVERINVENTORS LOWERY K. JONES JR. 8. JAMES o. TuRNEk THEIR ATTORNEYS March26, 1968 E JR, ET AL 3,375,497

MATRIX CONTROL CIRCUITRY USING GATE CONTROLLED UNIDIRECTIONAL SIGNALLINGDEVICES Filed April 27. 1964 3 Sheets-Sheet 2 Row OPERATE 2: RANK 20RESET MEANS REsET f MEANS MEANS 03 7o gqlqo Row 62 5 RANK SELECT 40 RowRANK [I6 SELECT [l8 MEANS DR'VER DRIVER MEANS w 59 '3 NE 62 22k 221)25\[:l\ I F6666 L +5OV.

0v. figs. TERM 40 POINT 60 I I -o.5v.

v +3.5V. figs 3 s +5OV. POINT I I USED As Row DRIVER 0V R6 3 .s ggL Lr-zcggm USED As RANK DRIVER 0v.

INVENTORS LOWERY K..JONES JR. a JAMES B. TURNER V. THEIR ATTORNE March26, 1968 Filed April 27, 1964 .JONES, JR ETAL MATRIX CONTROL CIRCUITRYUSING GATE CONTROLLED UNIDIRECTIONAL SIGNALLING DEVICES 3 Sheets-Sheeti3 ANODE OF TERM. To I RECT. 90 -av.

POINT 72 (FOR RANK 4V RESET) +3 5v TERM. I06

BASE I I TR. 76 TERM. I03

' +|v. PO|NT69 I TERM. I06 v -20\/.

- -+|v. TERM. |o3

POINT 89 [I H W (FOR ROW RESET) +75v. POINT as W 20 I +7sv. V L/ 0v|NvENToRs LOWERY K. JONES JR. 8. JAMES B. TURNEF'i THEIR ATTORNEYSUnited States Patent MATRIX CONTROL 'CIRCUITRY USING GATE CONTROLLEDUNIDIRECTIONAL SIGNAL- LING DEVICES Lowery K. Jones, Jr., and James D.Turner, Dayton, Ohio,

assignors to The National Cash Register Company, Dayton, Ohio, acorporation of Maryland Filed Apr. 27, 1964, Ser. No. 362,854 6 Claims.(Cl. 340-166) ABSTRACT OF THE DISCLOSURE An apparatus for energizingselected ones of a plurality of solenoids arranged in a matrixformation. Energization of a selected solenoid is controlled by twocoordinate groups of switching circuits, with one switching circuit ineach group being operated to complete an energizing path for a selectedsolenoid. Each switching circuit includes a unidirectional signaltranslating device, such as a silicon controlled rectifier, which may berendered conducting by means of a selection circuit, one of which isprovided for each coordinate group of switching circuits. Each switchingcircuit is subsequently rendered non-conducting by a reset circuit toterminate energization of the selected solenoid.

This invention relates generally to switching means. More particularly,the invention relates to switching means which may be employed incombination with one or more selected elements, such as solenoids, foroperating or energizing such elements, and also relates to arrangementsutilizing said switching means.

In one aspect of the present invention, a plurality of. elements, suchas solenoids, are disposed in a matrix formation, and a particularelement or solenoid of the matrix may be selected for operation orenergization by the selection of one switching means in each of twocoordinate groups associated with the matrix. The selection of theswitching means is accomplished by two selection means, one associatedwith each of the two coordinate groups of switching means, which causethe two selected switching means to commence conducting an operating orenergizing current. When the desired function has been accomplished bythe operated element or solenoid, a pair'of reset means, one of which isassociated with each group of switching means, is utilized to terminatethe operationor energization of the selected element or solenoid, byterminating conduction through the switching means.

The switching means of the present invention employs a unidirectionalsignal translating device having an anode,

conduction of the signal translating device is caused by operation of aseparate reset circuit to reverse-bias the signal translating device fora short period of time. One type of component which can be used as theunidirectional signal translating device is a silicon controlledrectifier, although other types of components could also be used, suchas, for example, a thyratron or a gate turn-01f switch. It should benoted that while the novel switching means is shown herein as beingemployed in a solenoid matrix, its use is not limited to such anapplication, since it is capable of use in many other areas whereinon-off switching means have utility.

Accordingly, an object of the present invention is to provide aneffective, simple, and inexpensive switching means.

Another object is to provide a switching means utilizing aunidirectional signal translating device having an anode, a cathode, anda control gate, said device being rendered conducting by application ofan appropriate signal to the control gate, and being renderednon-conducting by operation of a reset circuit to reverse-bias thesignal translating device.

An additional object is to provide means for controlling the operationof one or more elements, including switching means for selectivelyoperating the element or elements, selecting means for causingconduction of the switching means, and reset means for terminatingconduction of the switching means.

A further object is to provide a solenoid matrix including a pluralityof solenoids arranged in rows and ranks and capable of being selectivelyenergized, row switching means associated with each row, row selectmeans to select one of the row switching means, rank switching meansassociated with each rank, rank select means to select one of the rankswitching means, first reset means associated with all of the rowswitching means to reset a selected row switching means, second resetmeans associated with all of the rank switching means to reset aselected rank switching means, and reset operating means associated withthe first and second reset means for operation thereof, whereby onesolenoid in the matrix may be energized by the selection of a desiredrow and rank of the matrix by the row select means and the rank selectmeans, and whereby said selected solenoid may then subsequently bedeenergized by the reset operating means.

With these and incidental objects in view, the invention includescertain novel features of construction and com- =binati0ns of parts, apreferred form or embodiment of which is hereinafter described withreference to the drawings which accompany and form a part of thisspecification.

In the drawings:

FIG. 1 is a schematic diagram of a solenoid matrix and of the associatedelements for operating said matrix.

FIG. 2 is a simplified schematic diagram showing a single solenoid andthe associated elements for controlling the energization anddeenergization of said solenoid.

FIG. 3 is a schematic diagram of a switching circuit which may be usedin the arrangement shown in FIG. 1.

FIG. 4 shows a plurality of wave forms illustrating the signals atvarious points in the circuit of FIG. 3 during its operation.

FIG. 5 is a schematic diagram of a reset circuit which may be used withthe switching circuit of FIG. 3, particularly in the arrangement shownin FIG. 1.

FIG. 6 shows a plurality of wave forms illustrating the signals atvarious points in the circuit of FIG. 5 during its operation. I

Referring now to FIG. 1, a plurality of solenoids 11 are shown there,arranged in a matrix formation. As will be seen from the broken-awayportion of the matrix of FIG. 1, the matrix may be of any appropriatesize.

In series with each solenoid 11 is' an isolating diode 12, which may beof type 1N538, manufactured by International Rectifier Corporation,which serves to prevent undesired sneak paths by which solenoids inaddition to the selected solenoid might otherwise be energized. Eachserial combination of a diode and a solenoid is connected at one end toa row conductor 13, which extends to a row driver 14, and each serialcombination of a diode and a solenoid is connected at its other end to arank conductor 15, which extends to a rank driver 16. The row drivers 14and the rank drivers 16 are switching devices which control current flowin the row and rank conductors 13 and 15, and are of the same design,which may take the form of the circuit of FIG. 3, which will besubsequently described.

All of the row drivers 14 are in turn connected to a row select means17, and all of the rank drivers 16 are in turn connected to a rankselect means 18. The row select means 17 and the rank select means 18vcontrol selection of a particular row driver and a particular rankdriver for each solenoid which is to be energized, by causing theselected row driver and rank driver to commence conducting, thuscompleting a circuit for energizing the selected solenoid. No specificstructure is disclosed herein for these two select means, but any one ofseveral conventional types of structures may be used. For example, theraw and rank select means may be made up of registers, such as binaryflip-flop registers of appropriate lengths, with associatedbinary-to-decimal decoding net works connected to the row and rankdrivers, if the matrix is designed for a decimal system. Alternatively,sequential stepping switches may be used to energize lines associatedwith particular row and rank drivers.

Also shown in FIG. 1 are a row reset means 19, a rank reset means 20,and a reset operating means 21. The row reset means 19 is connected toall of the row drivers 14 and is capable of resetting, to anon-conducting condition, any row driver which has previously beenrendered conducting. The ran-k reset means 20 is connected to all of therank drivers 16 and is capable of resetting, to a non-conductingcondition, any rank driver which has previously been renderedconducting. The row reset means 19 and the rank reset means 20 areidentical in circuit configuration, and may take the form of the circuitof FIG. 5, which will be subsequently described.

The reset operating means 21 is connected to both the row reset means 19and the rank reset means 20, and is capable of controlling both of thesereset means to operate simultaneously. No specific structure isdisclosed herein for the reset operating means, but it may take the formof a free-running clock having a suitable pulse frequency, or it maytake the form of a logical network combining logical terms from variouscontrolling elements to produce a signal to operate the row and rankreset means when ever some particular combination of events takes place,in accordance with the configuration of the logical network.

Operating potential for the circuit of FIG. 1 may be provided by anysuitable power supply. In the illustrated embodiment, terminal 22 isconnected to a source of plus 50-volt D.C. potential, and terminals 23and 24 are connected to a source of plus .75-volt DC. potential. Anadditional terminal 25 is connected to a base reference potential, shownin FIG. 1 as ground. A conductor 26, connected to the plus 50-voltterminal 22, applies a plus SO-voltpotential to the row reset means 19and, over a diode 27, also applies a plus 50-volt potential to each ofthe rank drivers 16. The plus 75-volt terminals 23 and 24 are connectedto the row reset means 19 and the rank reset means 20, respectively, toapply a plus 75-volt potential thereto.

The grounded terminal 25 is connected over a conductor 29 to the rowreset means 19, the rank reset means 20, and, over a diode 30, to eachof the row drivers 14.

The matrix formation of solenoids shown in FIG. 1 provides a convenientarrangement whereby a particular solenoid 11. can be energized byselection of a corre sponding row driver 14 and rank driver 16 by therow select means 17 and the rank select means 18. The selected row andrank drivers are rendered conducting by their selection, and a circuitfor energizing the selected solenoid 11 is completed over a path such asthe one shown in' FIG. 2, which path extends from the plus 50-volt terminal 22 through the row reset means 19, the selected row driver '14,one of the conductors 13, the diode 12, the selected solenoid 11, one ofthe conductors 15, the

selected rank driver 16, and the rank reset means 20, to

the ground terminal 25.. The specific manner in which the variousdrivers and reset means are connected into the energizing circuit, aswell as the manner in which they function to provide the desiredenergization and deenergization of the solenoid 11, will subsequently bedescribed in detail. Suffice it to say for the present that conductionthrough the selected row and rank drivers 14 and 16 causes energizationof the solenoid 11 over the circuit of FIG. 2 described above, and thatthe subsequent operation of the row and rank reset means 19 and 20 bythe reset operating means 21 is effective to terminate conduction of therow and rank drivers 14 and 16', and thus to cause deenergization of theselected solenoid 11.

One use for which a solenoid matrix of the-type shown in FIG. 1 isadmirably adapted is for automatic or remote operation of the keyboardof a business machine, such as an accounting machine, a cash register,or an input-output device provided as one element of an onlinedata-processing system in which input-output devices are remotelycontrolled from a central data-processing station. In such anapplication of the solenoid matrix to the keyboard of a businessmachine, one solenoid is provided for each key of the keyboard, andenergization of the solenoid causes depression of the key. One exampleof a machine operated in such a manner is found in the copending U.S.patent application Ser. No. 308,382, filed Sept. 12, 1963, inventorsGeorge C. Beason and Calvin E. Stichweh, now U.S. Patent No. 3,158,318issued Nov. 24, 1964. One example of an on-line data-processing systemin which such a machine might be used is found in the copending U.S.patent application Ser. No. 335,184, filed Jan. 2, 1964, inventorsRobert M. Tink et al., now U.S. Patent No. 3,308,439, issued Mar. 7,1967. Of course it will be realized that the present invention is notlimited to this type of an application, and that the switching meansdisclosed herein could be used to operate a single solenoid, as well asa plurality of them. In addition, the switching means could, if desired,be utilized to control the operation of elements other than solenoids,such as relays, motors, etc i The switching circuit shown in FIG. 3 hasbeen found to be quite suitable for use as a row driver and a rankdriver in the solenoid operating circuit of FIG. 1. Input means for thecircuit of FIG. 3 are provided for by a terminal 40, which will, if thecircuit is used as a driver, be connected to the row select means 17 orto the rank select means 18. The terminal 40 is connected over aIZOD-ohm resistor 41 to a point 42 in the driver circuit. A first branchof the circuit from the point 42 extends over a 0.039-microfaradcapacitor 43 to a ground connection. A second branch of the circuitextends from the point 42 over three serially-connected diodes 44, whichmay be of type SG757, manufactured by Transitron Electronic Corporation,to a point 45. The resistor 41, the capacitor 43, and the diodes 44 forma noise-limiting network to prevent spurious noise pulses fromtriggering the circuit of FIG. 3.

From the point 45, the circuit extends over an 8000- ohm resistor 46 toa terminal 47, to which is applied a plus 12-volt source of DC.potential. The point 45 is also connected to the base circuit of asignal-translating device 48, which may be a PNP-type transistor-of typeNCRSZS, which has the same general characteristics as a transistor oftype 2N525 manufactured by General Electric Company. The emitter of saidtransistor is connected to ground, while the collector of saidtransistor is connected over a point 49 to one end of the primary of atransformer 50, which may be of the air core type. The other side of theprimary of the transformer 50 is connected over a point 51 and a3900-ohm resistor 52 to a terminal 53, to which is applied a source ofminus 20-volt DC. potential. From the point 51 a circuit branch. extendsover a point 54 and a 0.047-microfarad capacitor 55.to a groundconnection. A diode 56, which may be 'of type 1N949, manufactured byTransitron Electronic Corporation, is connected between the points49 and54,

and functions to prevent the transistor 48 from being damaged by aninductive kick from the transformer 50.

The secondary of the transformer 50 is connected at one end over points57 and 58 to a terminal 59. When the switching circuit of FIG. 3 is usedas a row driver, the terminal 59 is connected over one of the conductors13 to one side of a row of the diodes 12, and to one side of a diode 30,which may be of type 1N538, manufactured by International RectifierCorporation, the other side of which is connected to ground. When thecircuit of FIG. 3 is used as a rank driver, the terminal 59 is connectedto the associated rank reset means 20.

The other end of the secondary of the transformer 50 is connected over apoint 60 to the control gate of a unidirectional signal translatingdevice 61, shown in FIG. 3 as a silicon controlled rectifier, which maybe of type C12A, manufactured by General Electric Company. Other typesof unidirectional signal translating devices, such as a thyratron or agate turn-off switch, may be used in place of the silicon controlledrectifier, if desired. In such case, any necessary modifications of thecircuitry would be Well within the skill of one versed in the art.

The cathode of the silicon controlled rectifier 61 is connected to thepoint 58, and its anode is connected to a terminal 62. A IOOO-ohrnresistor 63 is connected between the points 57 and 60, between thecathode and the control gate of the silicon controlled rectifier 61.

It may be noted that when the switching circuit of FIG. 3 is used as arow driver, the terminal 62 is connected to the associated row resetmeans 19. When the circuit of FIG. 3 is used as a rank driver, theterminal 62 is connected over one of the conductors 15 to one side of arank of solenoids 11, and is also connected over said conductor 15 andover a diode 27, which may be of type 1N5 38, manufactured byInternational Rectifier Corporation, to the terminal 22, to which asource of plus- 50 volt DC. potential is applied.

The mode of operation of the circuit of FIG. 3 will now be described,with the aid of the Wave forms shown in FIG. 4, which represent signalsat various points in said circuit, during its operation. It should benoted that the various voltage levels shown in FIG. 4 and described inthe specification, as well as the specified values of the variouscomponents of the circuit of FIG. 3, are merely illustrative, and couldbe altered to meet different circuit requirements.

Let it be assumed that the circuit of FIG. 3 is being used as a rowdriver and initially has a potential of zero volts applied at terminal40, and a potential of plus 50 volts at terminal62, which is connectedover the row reset means 19 to the terminal 22, with terminal 59 beingconnected to one of the row conductors 13 of the matrix of FIG. 1.Current flow from the plus 12-volt terminal 47 over the resistor 46, thepoint 45, the diodes 44, the point 42, and the capacitor 43, to ground,causes the capacitor 43 to charge to plus 2 volts. The potential at thepoint 45 in the base circuit of the transistor 48 is at approximatelyplus 3.5 volts, as may be seen in FIG. 4, which is effective toreverse-bias the transistor and prevent its conduction. With thetransistor 48 cut ofi, there is no current flow through its collectorcircuit, and the potential at points 49 and 51 is therefore minus volts.The capacitor 55 accordingly charges to minus 20 volts.

The voltage level at the input terminal varies between logical levels ofzero volts and minus 8 volts. Let it now be assumed that an input pulseof minus 8 volts, of approximately 55 microseconds duration, is appliedto the terminal 40. The capacitor 43 accordingly discharges to apotential of minus 4 volts in'approximately 32 microseconds. The minus 4volts potential at point 42 is sufficient to override the combinedvoltage drop of the serially-connected diodes 44, and causes thepotential at point in the base circuit of the transistor 48 to go toapproximately minus 0.2 volt, which is sufficient to cause thetransistor to commence conducting. This completes a circuit from ground,through the transistor, emitter to collector, and through the primary ofthe transformer 50, discharging the capacitor 55.

A wave form induced by the primary on the secondary of the transformer50 is applied between the gate and the cathode of the silicon controlledrectifier 61, and is shown in FIG. 4 as it appears at point 60. Thepositive portion of the wave form, applied to the control gate, iseffective to fire the silicon controlled rectifier, causing it toconduct in the forward direction, establishing a conductive path betweenthe terminals 62 and 59. The wave form at terminal 59 is shown in FIG. 4for the situation in which the circuit of FIG. 3 is used as a rowdriver, and the wave form at terminal 62 is shown in FIG. 4 for thesituation in which the circuit of FIG. 3 is used as a rank driver. Itmay be noted that when the circuit is used as a row driver, the terminal62 remains at plus 50 volts potential, and when the circuit of FIG. 3 isused as a rank driver, the terminal 59 remains at zero volts potential.

Once the silicon controlled rectifier 61 has commenced conducting, itsgate has no further control over it. To terminate conduction of therectifier 61, it is reverse-biased, cathode to anode. This isaccomplished by the reset circuit of FIG. 5, which will now bedescribed.

It will be noted that a considerable portion of the reset circuit ofFIG. 5 is practically identical to the circuit of FIG. 3, and thereforethe description of that portion of the circuit, and its operation, willbe somewhat brief, since reference may be had to the description of thecircuit of FIG. 3 for a more complete explanation.

An input signal for the circuit of FIG. 5 is applied to a terminal 70,which is connected over a l210-ohm resistor 71 to a point 72, from whichone circuit branch extends over a 0.039-microfarad capacitor 73 toground, while a second branch extendsover three serially-connected diodes 74, which may be of type S6757, manufactured by TransitronElectronic Corporation, to a point 75 in the base circuit of a PNP-ty-petransistor 76, which may be of type NCR525, which has the same generalcharacteristics as a transistor of type 2N525, manufactured by GeneralElectric Company. A terminal-77, to which a source of plus 12-volt DC.potential is applied, is connected to the point 75 over an 8060-ohmresistor 78. As was mentioned in the description of FIG. 3, the resistor71, the capacitor 73, and thediodes 74 form a noise-limiting network toprevent spurious noise pulses from triggering the circuit of FIG. 5. 1

The emitter of the transistor-76 is connected to ground, while thecollector of said transistor is connected over a point 69 to one'end ofthe primary winding of a transformer 79, which maybe of the air coretype. The other end of the primary winding of the transformer 79 isconnected to a point 80. One circuit branch extends from the point 80over a 3900-ohm resistor 81 to a terminal 82, to which is applied asource of minus 20-volt D.C potential. -A second branch extends from thepoint 80 over a 0.047-microfarad capacitor 83 to ground. Between thepoints 69 and 80 is connected a diode 84, which may be 'of type 1N949,manufactured by Transitron Electric Corporation, and which is providedto prevent damage to the transistor 76 by an inductive kick from thetransformer 79.

One end of the secondary winding of the transformer 79 is connected overpoints 85 and 86 to a terminal 87, to which may .be applied a groundconnection. The other end of the secondary winding of the transformer 79is connected over a diode 88, which may be of type DR453, manufacturedby Sylvania Electric Products, Incorporated, and a point 89 to thecontrol gate of a silicon controlled rectifier 90, which may be of typeC12A, manufactured by General Electric Company. Between the points 85and 89 is connected at IOOO-ohm resistor 91.

The cathode of the silicon controlled rectifier 90 is connected at apoint 92 to a conductor extending between the point and a point 93.Between the point 93 and a point 94 are connected in parallel twocapacitors 9'5 and 96, having a capacitance of 10 microfarads each.

The anode of the silicon controlled rectifier 90 is connected to one endof the primary winding of an iron core transformer 97. In theillustrated embodiment, this is a 1:1.76 step-up transformer with nophase inversion. The other end of the primary winding of the transformer97 is connected to a point 98, One circuit path extends from the point98 to the previously-mentionedpoint 94, and a second circuit pathextends from the point 98 over a 100- ohm resistor 99 to a terminal 100,to which is applied a source of plus 75-volt DC. potential.

The secondary winding of the transformer 97 is connected at one end overpoints 101 and102 to a terminal 103, and is connected at its other endover points 104 and 105 to a terminal 106. A diode 107, which may be oftype 1036, manufactured by International Rectifier Corporation, isconnected between the two points 101 and 104, while a serial combinationof a *.0l-microfared capacitor 108 and a 75-ohm resistor 109, providedto cause attenuation of undesired voltage transients at the time thedriver turns off, is connected between the points 102 and 105.

When the circuit of'FIG. is used as a row reset means, in associationwith one or more row drivers, the terminal 106 is connected to a plusSil -volt D.C. source of potential, and theterminal 103 is connectedover a conductor to the terminal 62 of the circuit of FIG. 3, it beingassumed that the circuit of FIG. 3 is being used as a row driver.

When the circuit of FIG. 5 is used as a rank reset means in associationwith one or more rank drivers, the terminal 103 is connected to ground,and the terminal 106 is connected to a conductor which, in turn, isconnected to the terminal 59 of the circuit of FIG. 3, it being assumedthat the circuit of FIG. 3 is used as a rank driver. The properorientation of the various reset means and drivers, with respect to eachother, in a circuit for energizing a particular solenoid, is shown inFIG. 2, with various terminals designated.

The mode of operation of the circuit of FIG. 5 will now be described,with theaid of the wave forms shown in FIG. 6, which represents signalsat various points in said circuit, during its operation. It should benoted that the various signals described in the specification and shownin FIG. 6, as well as the specified values ofthe various components ofthe circuit of FIG. 5, are merely illustrative, and could be altered tomeet difierent circuit requirements.

let it be assumed that the circuit of FIG. 5 is being used as a rowreset means, and initially has a potential of zero volts applied atterminal 70, and a potential of plus 50 volts at terminal 106, withterminal 103 being connected to the terminal 62 of one or a plurality ofrow drivers, said row drivers using the circuit shown in FIG. 3. If oneof the row drivers has previously been rendered conducting by an inputpulse of minus 8 volts at its terminal 40, then a current path forenergizing a solenoid 11 has been established, and extends from the plus50-volt terminal 22 (FIGS. 1 and 2) over the terminal 106 of FIG. 5,through the low-impedance secondary winding of the transformer 97, overthe terminal 103-, over a conductor to the terminal '62 of the selectedrow driver, and thence through the remainder of the energizing circuitas shown in FIGS. 1 and 2.

through its collector circuit, and the potential at points 78 and 80 isminus 20 volts, so that the capacitor 83 is charged to minus 20 volts.

When an input pulse of minus 8 volts is terminal 70 of the circuit ofFIG. 5, the capacitor 73 discharges to minus 4 volts, as shown by thewave form for point 72 in FIG. 6, which causes the transistor 76' tocommence conducting, as shown by the wave form for point 69, therebydischarging the capacitor 83 through the primary of the transformer 79,in the same manner as described in connection with the circuit of FIG.3.

This causes a wave form induced by the primary on the secondary of thetransformer 79 to be applied between the gate and the cathode of thesilicon controlled rectifier 90. This wave form, applied tothe controlgate of the rectifier over the diode 88 and the point 89, as may be seenin FIG. 6', is elfective to cause it to commence conducting in theforward direction.

The storage capacitors and 96- have previously been charged to the levelof the plus 75-volt supply. Firing the silicon controlled rectifier 90discharges the capacitors 95 and 96 into the primary of the transformer97. This action produces a transient oscillatory effect, and a resultingsignal is induced in the secondary winding of the transformer 97. Also,because of the transient oscillatory effect, the silicon controlledrectifier 90 is reverse-biased, by a negative swing of the signal on itsanode, as shown in FIG. 6, and the conduction of said rectifier isthereby terminated. The secondary of the transformer 97 is in serieswith the path conducting D.C. current from the plus 50-volt terminal 22through the row driver to the selected solenoid 11. Opposing voltageinduced in the secondary winding of the transformer 97 as a result ofthe discharge of capacitors 95 and 96 produces a large counter EMF,which takes the form of a -volt negative going spike on the terminal103, as shown in FIG. 6, and which reverse-biases the previouslyconducting silicon controlled rectifier 61 of the selected row driver.This causes the silicon controlled rectifier to cease conducting, andthereby interrupts the energizing circuit for the solenoid 11.

In a like manner, the conducting silicon controlled rectifier 61 of theselected rank driver is reverse-biased by a 125-volt positive-goingspike on the terminal 106 of its associated rank reset means at the sametime, as shown in FIG. 6, and conduction of the silicon controlledrectifier 61 of the selected rank driver is thereby terminated.

The diode 107 is provided in the circuit of FIG. 5 in order to clamp thepotential at the anode of the silicon controlled rectifier 61 in the rowdriver at no more than plus 50 volts, in order to protect saidrectifier. If the diode 107 were not included in the circuit, it ispossible that the transient oscillatory efiect in the circuit of FIG. 5might result in producing a momentary pulse of. greater than plus 50volts which could exceed the rating of the silicon controlled rectifier61 and thereby damage it.

If desired, two secondaries may be used with a single primary of thetransformer 97, with one secondary being associated with the rankdrivers and the other being associated with the row drivers. This wouldenable the use of a single reset circuit of the type shown in FIG. 5,which would be effective to terminate conduction simultaneously of boththe selected row driver and the selected rank driver.

It will be seen from the above description that the circuits of FIGS. 3and 5 may be combined to provide a simple and effective switching meansfor controlling conduction through a circuit path, with the circuit ofFIG. 3 providing means to initiate conduction through the unidirectionalsignal translating device 61, and the circuit of FIG. 5 providing meansto terminate the conduction through said device.

While the form of device shown and described herein is admirably adaptedto fulfill the objects primarily stated, it is to be understood that itis not intended to confine the applied to the What is claimed is:

I. A solenoid matrix comprising, in combination,

a plurality of solenoids arranged in rows and ranks and capable of beingindividually selectively energized; a row switching means associatedwith each row and including a unidirectional signal translating devicehaving an anode, a cathode, and a control gate connected so that asolenoid energizing circuit extends through the anode and cathodethereof, which device may be selectively rendered conducting ornon-conducting to establish or interrupt an energizing path forenergizing a selected solenoid of the QII a row switching meansassociated with each row andincluding a unidirectional signaltranslating device having an anode, a cathode, and a control gateconnected so that a solenoid energizing circuit extends through theanode and cathode thereof;

row select means associated with the control gate of the unidirectionalsignal translating device of each row switching means to selectivelyoperate the unidirectional signal translating device of one of said rowswitching means;

a rank switching means associated with each rank and including aunidirectional signal translating device having an anode, a cathode, anda control gate connected so that a solenoid energizing circuit exmatrix;1 tend through the anode and cathode thereof;

row select means associated with the control gate of the rank selectmeans associated with the control gate of unidirectional signaltranslating device of each row the unidirectional signal translatingdevice of each switching means to selectively render conducting the rankswitching means to selectively operate the uniunidirectional signaltranslating device of the row directional signal translating device ofone of said switching means for the selected row; rank switching means;

a rank switching means associated with each rank and first reset meansassociated with the unidirectional sigincluding a unidirectional signaltranslating device nal translating devices of all of the row switchinghaving an anode, a cathode, and a control gate conmeans and capable ofresetting the unidiretcional nected so that a solenoid energizingcircuit extends signal translating device of any row switching meansthrough the anode and cathode thereof, which device which is operated;may be selectively rendered conducting or nonsecond reset meansassociated with the unidirectional conducting to establish or interruptan energizing signal translating devices of all of the rank switchpathfor energizing a selected solenoid of the ing means and capable ofresetting the unidirectional matrix; signal translating device of anyrank switching means rank select means associated with the control gateof the which is operated; and

unidirectional signal translating device of each rank reset operatingmeans capable of operating the first and switching means to selectivelyrender conducting the second reset means to cause resetting of theuniunidirectional signal translating device of the rank directionalsignal translating device of any operated switching means for theselected rank; row switching means and any operated rank witchfirstreset means associated with all of the row switching means, whereby onesolenoid in the matrix may ing means and including output means, anoscillatbe energized by selection of a row and rank of ing circuit forestablishing a signal on the output the matrix by the rowselect meansand the rank means, a unidirectional signal translating device havselectmeans, and whereby said select solenoid may ing an anode and a cathodeconnected to the oscilthen subsequently be deenergized by the resetoperlating circuit and also having a control gate, and inating means.

put means connected to the control gate for con- 4. The solenoid matrixof claim 3 in which the unitrolling conduction of the unidirectionalsignal translating device, said first reset means being capable ofterminating conduction of the unidirectional signal translating deviceof any row switching means; second reset means associated with all ofthe rank directional signal translating devices are silicon controlledrectifiers.

5. A switching device for controlling elements arranged in rows andranks in a matrix comprising, in combination,

switching means and including output means, an oscillating circuit forestablishing a signal on the output means, a unidirectional signaltranslating device having an anode and a cathode connected to a rowswitching means associated with each row of the matrix and including aunidirectional signal translating device having an anode, a cathode, anda control gate connected so that an element controlling cirtheoscillating cir i an also havmg a Control gate, cuit extends through theanode and cathode thereof; and PP means cQnnected to f 01 E for rowselect means associated with the control gate of the C011t1'011 111gcon'ductlmf of the unldlfectlonal slgflal unidirectional signaltranslating device of each row trflnslatlng devlqe, Sa1d secoml resetmeans switching means to selectively operate the unidireccflpable oftermlnatlng conquwon of the l tional signal translating device of one ofsaid row tional signal translating device of any rank switchi hi mgmeans; and a rank switching means associated with each rank resetoperating means associated with the input means of the matrix andincluding a unidirectional signal of the first and second reset means,and capable of translating device having an anode, a cathode, andoperating said unidirectional signal translating dea control gateconnected so that an element convices of said first and second resetmeans to cause trolling circuit extends through the anode andcathtermination of conduction of the unidirectional sigode thereof; naltranslating devices of the previously selected row rank select meansassociated with the control gate of switching means and rank switchingmeans, whereby the unidirectional signal trnaslating device of each onesolenoid in the matrix may be energized by selec- 5 rank switching meansto selectively operate the unition of a desired row and rank of thematrix by the directional signal translating device of one of said rowselect means and the rank select means, and rank switching means;whereby said selected solenoid may then subsefirst reset meansassociated with' the unidirectional quently be deenergized by the resetoperating means. signal translating devices of all of the row switching2. The solenoid matrix of claim 1, in which the uni- 7 means and capableof resetting any row switching directional signal translating devicesare silicon controlled means which is operated;

rectifiers. second reset means associated with the unidirectional 3. Asolenoid matrix comprising, in combination, signal translating devicesof all of the rank switching a plurality of solenoids arranged in rowsand ranks and means and capable of resetting any rank switching capableof being individually selectively energized; means which is operated;and

1 1 1 2 reset operating means capable of operating the first ReferencesCited and second reset means to cause resetting of the uni- UNITEDSTATES PATENTS directional signal translatmg device of any operated rowswitching means and any operated rank switch- 2,889,508 6/1959 MCCOY eta1 340'166 ing means, whereby one of the elements of the ma- 5 21964165712/1960 Page X 'trix may be controlled by selection of a row and rank2,992,410 7/1961 Groth et 340" 166 of the matrix by the row select meansand the rank 3,129,408 4/1964 Hechler 340-166 select means, and wherebythe control of said se- 3,286,234 11/1966 Hogrefe lected element maysubsequently be terminated by 3,280,267 10/1966 Feucht 4 340-466resetting of the row and rank switching means by 0 the first and secondreset means under control of the JOHN CALDWELL, Prlmary Exammerf resetoperating means. 6. The switching device of claim 5 in which the unidi-NEIL READ Exammer" rectional signal translating devices are siliconcontrolled H. I. PITTS, AssistantExaminer. rectifiers.

